A comparative study of swelling properties of hydrogels based on poly(acrylamide‐co‐methyl methacrylate) containing physical and chemical crosslinks

Poly (acrylamide‐co‐methyl methacrylate) hydrogels of different ratios were prepared by using chemical and physical crosslinks to study the effect of nature of crosslinks on swelling behavior of hydrogels. The chemically crosslinked gels were prepared by using NN′‐methylene bis acrylamide, while physically crosslinked hydrogels were prepared by precipitation polymerization method, using dioxane as solvent. Detailed swelling kinetics such as swelling ratio, transport exponent n, diffusion coefficient D and the effect of pH on equilibrium swelling studies. The study revealed that the nature of crosslinks alter the swelling characteristics of the hydrogel. In chemically crosslinked hydrogels the water transport is Fickian in nature, while in the case of the physically crosslinked hydrogels the water transport mechanism is anomalous indicating major change in relaxation mechanism due to nature of crosslinks. The results also indicate that with increasing acrylamide content the swelling ratio of the hydrogels were also increased, but the transport exponent n remains nearly constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 779–786, 2003     

Physical Properties of Sn1−x Fe x O2 Powders Using Solid State Reaction

Iron-doped SnO₂ diluted magnetic semiconducting powders (Sn_1?x Fe _x O₂, x=0.00, 0.03, 0.05, 0.07, 0.10, and 0.15) were synthesized by a simple solid state reaction followed by vacuum annealing and studied the effect of Fe dopant concentrations on structural, optical, and magnetic properties of the synthesized samples. From the X-ray diffraction, it was confirmed that the samples prepared at lower dopant concentrations were tetragonal in structure whereas the samples prepared at higher dopant concentration exhibited orthorhombic SnO and Fe₂O₃ phases along with tetragonal SnO₂ structure. FT-IR spectrum has been used to confirm the formation of Sn–O bond. The optical band gap of the Sn_1?x Fe _x O₂ powders was increased from 3.6 eV to 3.7 eV with increase of dopant concentration. Raman spectroscopy measurement revealed that the broadening of the most intense Raman peak observed at 630 cm^?1 with Fe doping, conforming that the Fe ions are substituted at the Sn sites in the SnO₂ lattice. Vibrating sample magnetometer measurements confirmed that the Sn_1?x Fe _x O₂ powders were ferromagnetic at room temperature.     

Structural and Magnetic Properties of Co diffused CdTe Nanocrystalline Thin Films Deposited by Electron Beam Evaporation

Co diffused cadmium telluride (CdTe) nanocrystalline thin films with different Co content were prepared by depositing CdTe/Co stacked layers on glass substrates at 373 K using electron beam evaporation technique. The effect of Co content on structural, morphological, chemical, Raman, and magnetic studies were carried out. X-ray diffraction (XRD) patterns confirmed that all Co diffused CdTe films are in zinc blende structure. The lattice parameter increased with increase of Co content. The high-resolution scanning electron microscopy (HRSEM) images illustrated the grain size of the films. EDAX data confirmed the presence of Co, Cd, and Te with nearly stoichiometic. Raman spectra revealed peaks corresponding to A1, TO, and LO modes of CdTe and gradual shift in peak position. The increase in intensity confirmed the incorporation of Co into CdTe host lattice. Magnetic measurements showed a clear well-defined room temperature ferromagnetic hysteresis loop.     

Regionalization of the territory of Russia according to water hazard

Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 8, pp. 11–13, August, 1993.     

Structural,optical and magnetic properties of Cu doped CdSe powders prepared by solid state reaction method

Cu doped CdSe powders were synthesized by solid state reaction method and studied the effect of Cu doping concentration on structural, optical and magnetic properties of the prepared samples. From XRD study it was found that the lattice constant increased with increase of Cu doping concentration. A clear blue shift was observed in the samples from optical studies. From the magnetic measurements, it was found that the samples were room temperature ferromagnetic in nature and strength of magnetic moment increased with increase of doping concentration. These synthesized powders are dilute magnetic semiconductors and are very promising candidates for ‘Spintronic’ device applications.     

Atmospheric Fine and Coarse Mode Aerosols at Different Environments of India and the Bay of Bengal During Winter-2014: Implications of a Coordinated Campaign

In this paper, we present mass concentrations of particulate matter [PM_2.5, PM₁₀ size fractions and total suspended particulates (TSP)] measured simultaneously over land stations (Kullu, Patiala, Delhi, Ajmer, Agra, Lucknow, Varanasi, Giridih, Kolkata, Darjeeling, Jorhat, Itanagar, Imphal, Bhubaneswar, and Kadapa), mostly distributed across the Indo-Gangetic plain (IGP) of India as well as in the marine atmosphere over Bay of Bengal (BoB) in the period from 20 January to 3 February, 2014. The main objective of this study was to quantify the continental outflow of particulates (PM_2.5, PM₁₀ and TSP) from IGP and associated regions into the BoB along with low level north-east wind flow during winter monsoon period. The present study provides a glimpse of the aerosol loading over the IGP region. During this campaign, the highest average PM_2.5 (187.8 ± 36.5 µg m^?3, range 125.6–256.2 µg m^?3), PM₁₀ (272.6 ± 102.9 µg m^?3, range 147.6–520.1 µg m^?3) and TSP (325.0 ± 71.5 µg m^?3, range 220.4–536.6 µg m^?3) mass concentrations were recorded at Varanasi, Kolkata and Lucknow over middle and lower IGP regions. The PM_2.5 (average 41.3 ± 11.9 µg m^?3; range 15.0–54.4 µg m^?3), PM₁₀ (average 53.9 ± 18.9 µg m^?3; range 30.1–82.1 µg m^?3) and TSP (average 78.8 ± 29.7 µg m^?3; range 49.1–184.5 µg m^?3) loading over BoB were found to be comparable to land stations and suggests possible continental outflow. Over the continental region, the highest PM_2.5/PM₁₀ ratio was recorded at Delhi (0.87). The PM_2.5/PM₁₀ ratio over BoB (0.77) was found to be quite high and comparable to Varanasi (0.80) and Agra (0.79).     

Design of compact patch type curved frequency selective surface

Miniaturized FSS is very useful in communication system. It is obtained by lowering the resonant frequency. Many good research works are reported on compact planar FSS, but it is challenging to decrease the resonant frequency in case of curved FSS. This article deals with the design and fabrication of compact patch type curved FSSs. Here maximum 50.31% compactness is achieved in semicylindrical curved FSS with square slit. Also the parametric studies have been analyzed by introducing same slit in circular and hexagonal patch elements of the curved FSSs. The proposed design has been fabricated. Simulated result has been ratified with experiment result.     

ASRmiRNA: Abiotic Stress-Responsive miRNA Prediction in Plants by Using Machine Learning Algorithms with Pseudo K-Tuple Nucleotide Compositional Features

MicroRNAs (miRNAs) play a significant role in plant response to different abiotic stresses. Thus, identification of abiotic stress-responsive miRNAs holds immense importance in crop breeding programmes to develop cultivars resistant to abiotic stresses. In this study, we developed a machine learning-based computational method for prediction of miRNAs associated with abiotic stresses. Three types of datasets were used for prediction, i.e., miRNA, Pre-miRNA, and Pre-miRNA + miRNA. The pseudo K-tuple nucleotide compositional features were generated for each sequence to transform the sequence data into numeric feature vectors. Support vector machine (SVM) was employed for prediction. The area under receiver operating characteristics curve (auROC) of 70.21, 69.71, 77.94 and area under precision-recall curve (auPRC) of 69.96, 65.64, 77.32 percentages were obtained for miRNA, Pre-miRNA, and Pre-miRNA + miRNA datasets, respectively. Overall prediction accuracies for the independent test set were 62.33, 64.85, 69.21 percentages, respectively, for the three datasets. The SVM also achieved higher accuracy than other learning methods such as random forest, extreme gradient boosting, and adaptive boosting. To implement our method with ease, an online prediction server “ASRmiRNA” has been developed. The proposed approach is believed to supplement the existing effort for identification of abiotic stress-responsive miRNAs and Pre-miRNAs.     

Plasmonic Lipid Bilayer Membranes for Enhanced Detection Sensitivity of Biolabeling Fluorophores

Plasmonics based sensing, using the surface plasmon resonance of metal nanoparticles, has been effectively demonstrated in various applications. Extending this methodology to cell and artificial lipid bilayer membranes is extremely beneficial in enhancing the sensitivity of the detection of binding and cellular transport of molecules across such membranes. Here, the creation of an artificial plasmonic biomembrane template is demonstrated and used to show the enhanced detection sensitivity of certain widely used biomarker molecules. The efficacy of these templates is explained in terms of the ability of the hydrophobic polymer grafted gold nanoparticles used to organize, penetrate, and fluidize the membranes. The enhancement of photoluminescence of the dye molecules used occurs over a reasonably large spectral range as compared to the plasmon resonance of gold nanoparticles. The results could, possibly, be extended to cellular membranes with relevant modifications, as well as to the detection of any other biological molecule appropriately labeled with fluorescent dye molecules, and demonstrate the versatility of these plasmonic bioinspired platforms as potential biochemical sensors.